JPH03227733A - Constant speed running control device - Google Patents

Abstract

PURPOSE:To enhance convergence properties to a target speed by limiting the magnitude of vehicle speed deviation, and thereby making the limit value at the time of negative vehicle speed deviation different from that at the time of positive vehicle speed deviation in a device in which control signals are outputted based on the integrated value of deviation between the target speed and running speed. CONSTITUTION:In a vehicle which runs at a constant speed with the opening of an engine throttle valve adjusted via a negative pressure actuator 20 by controlling respective solenoids SL1 and SL2 by a CPU, vehicle speed detected by a speed detecting circuit 30 when a set switch SSW is turned on is made to be a target vehicle speed so that control signals are outputted in response to the integrated value of deviation from running speed. In this case, when deviation is positive, if deviation exceeds the first specified value, the first specified value is integrated, and if deviation is less than the first specified value, deviation is then integrated. On the other hand, when deviation is negative, if deviation is less than the second specified value (< the first specified value), the second specified value is integrated, and if deviation exceeds the second specified value, deviation is then integrated so that the integrated value is obtained.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention compares the running speed of a vehicle with a target speed, and operates a throttle valve in order to make the running speed equal to the target speed. This invention relates to a constant speed travel control device that opens/closes.

(Prior Art) A constant speed cruise control device compares a traveling speed with a target speed, and when the former is low, drives the throttle valve to open, and when the former is high, drives the throttle valve to close.

The throttle valve is driven to open and close by a negative pressure actuator that expands and contracts a diaphragm using, for example, negative pressure in an intake manifold. By communicating the internal space of the diaphragm with the intake manifold, the diaphragm retracts and the throttle valve is driven to open, and by communicating with the atmosphere, the diaphragm expands and the throttle valve is driven to close (for example, Japanese Patent Laid-Open No. 62-68138 Publication) 6 The throttle valve opening degree is determined by the time ratio (duty) for alternately switching the diaphragm internal space between the intake manifold and the atmosphere, and communicating the intake manifold and the atmosphere. This duty (throttle valve opening) is determined as follows.

DV=DS+GVX (RM ROCTXA)・
・ ・ (1) Dv=output duty, DS: initial set duty,
RM: Memory vehicle speed (target vehicle speed), R[l: Current vehicle speed (
(vehicle speed), A: Curse acceleration, GV: Integral gain, CT:
In the compensation time equation above, the initial set duty DS is a duty that provides the throttle opening required for traveling at the stored vehicle speed under standard driving conditions (flat road), and is determined for each stored vehicle speed. In addition, GVX (RM Ro CT
In the term A), the current vehicle speed R6 at the time of disturbance is stored as the vehicle speed R.
This is a term for convergence to M. By the way, 0 for example DS
=40% (RM=80ka+/h), GV =
6.0%/(km/h), CT = 1.4s
When the vehicle enters the uphill state while driving on a flat road in EC, the vehicle cannot go uphill when the output duty DV=DS=40%, and the vehicle speed begins to decrease. Therefore, the output duty DV is GVX (RM-Ro CT
It increases due to the influence of item A). At this time, current acceleration A = -0.2 km/h/sec.

Difference between stored vehicle speed RM and current vehicle speed RO (vehicle speed deviation) RM
If Ro=3.0km/h, D V =40+6
．． 0X (3,0+ 1.4 x 0.2) = 59.
It becomes 68%. However, since the integral gain GV is a value that is matched so that it converges to avoid hunting, surge, etc. when a disturbance occurs under standard driving conditions (flat road), the vehicle speed converges to the memorized vehicle speed RM when the vehicle is on the hill. Its value is not as large as it needs to be. Therefore, if the climbing condition continues, the vehicle speed gradually decreases until it reaches a level determined by the climbing slope, and then balances out (this is called a set deviation), which causes a problem.

Therefore, it has been proposed to determine the duty using an arithmetic expression obtained by adding an integral term to the above equation (1), such as the following equation (2) (Japanese Patent Laid-Open No. 62-68138).

DV: DS+GVX (RM ROCTXA)+DI
... (2) D I = D
I+ΔDr DI: Integral duty, ΔD■: Arbitrary value determined by vehicle speed deviation RM-Ro According to the term of integral duty DI in equation (2), when the above-mentioned set deviation occurs at the time of pitching, DI gradually increases, and the output duty In order to increase DV, vehicle speed RQ converges to memorized vehicle speed RM.

However, since the integral value (positive value) increases when pitching,
When the rider changes from climbing to descending, the integral value causes a delay in closing the throttle valve, slowing down the vehicle speed, and causing vehicle speed overshoot. When the vehicle changes from descending to a flat road or climbing, the integral value (negative value) decreases when descending, so the vehicle speed increases slowly and undershoot occurs. In addition, according to the above-mentioned formula (2), if the driver increases the acceleration by depressing the accelerator pedal during constant speed control, the vehicle speed deviation RM
Ro occurs, negative integration is performed, the negative pressure actuator moves in the direction of closing the throttle valve, and when the driver releases the accelerator pedal, the vehicle speed rapidly decreases and undershoot occurs.

In order to solve this problem, it has been proposed to provide a sensor that detects the driver's accelerator operation and to stop integrating the vehicle speed deviation when the accelerator pedal is depressed (Japanese Patent Laid-Open No. 61
-119431 publication).

(Problem to be Solved by the Invention) However, even if the accelerator pedal is depressed, if the throttle valve is not driven to a higher degree of visibility than the drive opening by the actuator of the constant speed control system, Stopping the integration has the disadvantage of delaying acceleration. Therefore, it is necessary to add hardware elements, such as using an accelerator depression amount sensor and an actuator opening sensor in combination, and stopping or resetting the integration only when the accelerator depression amount exceeds the actuator opening.

The cost will be high.

The present invention allows g
: The purpose of the present invention is to suppress the occurrence of undershoot/overshoot as described above when the vehicle is traveling on a slope, when the accelerator pedal is depressed, when the vehicle is stepped down, etc.

[Structure of the invention]

(Means for solving problems) In order to achieve the above object, in the present invention.

Combined with the vehicle's throttle valve. Throttle drive means (20): Vehicle speed detection means (L S W + M ag ) that generates an electric signal according to the speed of the vehicle.
: Then, the deviation (Rs Ro) between the target speed (RM) and the running speed (Ro) is integrated, and the direction in which the running speed (Ro) matches the target speed (RM) is calculated according to the integrated value (DI). In a constant speed cruise control device comprising: a speed control means (CPU) that energizes a throttle drive means (2o), the speed control means (CPU) calculates the difference (ΔDI)=target speed (Rs)−travel speed ( If Ro) is positive, the deviation (ΔD
When I) is the first predetermined value (5,0 Peng/h), the first predetermined value is integrated, and when it is less than the first predetermined value, the deviation (ΔD
I), and if the deviation (ΔDI) is negative, the deviation (ΔD
When I) is less than or equal to a second predetermined value (-0, 2/h) whose absolute value is smaller than the first predetermined value, the second predetermined value is integrated, and when it exceeds the second predetermined value, the deviation is calculated. (ΔDI) is integrated.

(Function) In this way, when integrating the vehicle speed deviation (RM-RO), there is a limit (upper limit:
5.0 km/h, lower limit knee 0.2 km/h), and furthermore, a limit value (-0
, 2km/h) is made smaller than the limit value (5, OK) when the vehicle speed deviation (RM-RO) is positive, so it is necessary when accelerating by pressing the accelerator pedal (when the deviation is negative). As described above, the integrated value is suppressed from increasing to the negative side, and undershoot does not occur when the accelerator is released.
If the deviation is positive and less than the first predetermined value, the integrated value increases quickly, so the traveling vehicle speed quickly converges to the target vehicle speed when the vehicle is on the hill.

In addition, when descending, if the deviation becomes negative, the duty becomes small and the opening immediately becomes idling. For example, when driving on a flat road at 80 km/h, the duty is 40%.
However, the throttle opening is about 10%, and when the deviation becomes negative, the throttle opening immediately reaches the lower limit of the idling opening. Therefore, the integrated value when the deviation is negative (
There is no problem in that the influence of negative values) is almost eliminated and the limit value of one negative deviation is small.

By accumulating small but negative deviations.

The integrated value is adjusted when moving from pitching to flat road, and overshoot is suppressed.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Example) FIG. 1 shows an outline of the configuration of an embodiment of the present invention.

This embodiment is applied to a vehicle equipped with an automatic transmission with a lock-up function. In this embodiment, a microcomputer CPU is used to control the device. The power supply for this electric circuit is via the switch IGS which is linked to the ignition switch.

It is supplied from the on-board battery BT. Voltage stabilization circuit VR
Power converted into a stable voltage of 5V by G is applied to a logic circuit such as a microcomputer CPU.

BSW is a brake switch that is linked to the operation of a brake pedal (not shown), CSW is a clutch switch that is linked to the operation of a clutch pedal (not shown), and SSW is
The set switch R3W is a set switch for commanding constant speed driving, and the resume switch R3W is a resume switch for commanding restart of constant speed driving.
This is a reed switch for detecting vehicle speed. A permanent magnet Mag connected to the speedometer cable is arranged near the reed switch LSW. LP is a stop lamp.

One end of the switch BSW is connected to the switch IGS via a fuse FS2, and the other end of the switch BSW is grounded via a stop lamp LP. switch B
Both ends of SW are connected to input ports PI and P2 of the microcomputer CPU via interface circuits IFC, respectively. In addition, switches csw, s
sw.

R5W and LSW are all grounded at one end, and the other end is connected to the input port P3. of the microcomputer CPU via the interface circuit IFC. P4. P
5 and P6. Note that the input port P6 of the microcomputer CPU is an external interrupt input terminal.

Microcomputer CPU output ports P7 and P
8 have solenoid drivers SDI and SD, respectively.
2, solenoids SLI and SL2 are connected. These solenoids SLI and SL2 operate as a control solenoid and a release solenoid for a negative pressure actuator, which will be described later, respectively.

A motor driver MD that energizes a drive motor M that drives a vacuum pump vP is connected to an output port P9 of the microcomputer CPU.

The output port P10 of the microcomputer CPU is
Automatic transmission is connected. This automatic transmission will be explained.

The input shaft of a torque converter 21 with a direct coupling (lock-up) clutch is coupled to the rotating shaft 29 of the engine. Transmission mechanism 2
3 input shafts are connected. An output shaft 24 of the mechanism 23 drives an axle (not shown) via a propeller shaft (not shown), a differential (not shown), and the like.

Torque converter 21. The overdrive mechanism 22 and the gear transmission mechanism 23 are driven by a hydraulic circuit including a shift lever, a shift valve, a switching solenoid valve 26, 27, and a lock-up solenoid valve 28. A shift lever position sensor 25 detects the set position of the shift lever. A signal indicating the set position of the shift lever is given to a speed change controller 31 mainly composed of a microcomputer.

Also.

The open/close signal of the reed switch LSW is given to the speed detection circuit 30, and the circuit 30 sends the vehicle speed signal to the controller 3.
Give to 1.

The configuration of the automatic transmission device described above is similar to that already presented by the present applicant in Japanese Patent Application Laid-Open No. 56-39354. However, there is a slight change in which the speed gear is shifted to a lower gear (downshift) in response to a downshift instruction from the microcomputer CPU.

The main changes have been made to the control program. An outline of the operation of this automatic transmission and the contents of control operations in response to instructions from the microcomputer CPU will be described later with reference to FIG.

FIG. 2 shows the configuration of the negative pressure actuator 20 shown in FIG. 1.

The housing 1 consists of two parts 1a and 1b.

The diaphragm 2 is sandwiched between these two parts la and lb. A space surrounded by the diaphragm 2 and the housing la is a negative pressure chamber, and a space surrounded by the diaphragm 2 and the housing lb communicates with the atmosphere. Reference numeral 3 denotes a compression coil spring inserted between the housing la and the diaphragm 2, which pushes the diaphragm 2 back to the position of the imaginary line when the pressure in the negative positive chamber is close to atmospheric pressure.

A protrusion 4 is fixed near the center of the diaphragm 2.

It is connected to the link of the throttle valve 5.

The housing 1a is provided with a negative pressure intake lower communicating with the intake manifold 6 and atmospheric air intakes 8 and 9.

10 is a negative pressure control valve, and 11 is a negative pressure release valve, both of which are fixed to the housing 1a.

The movable piece 12 of the negative pressure control valve lO is tiltable about P as a fulcrum, and a tension coil spring 13 is connected to one end.
The other end faces the control solenoid SLI. Both ends of the movable piece 12 function as valve bodies, and they open the negative pressure intake lower, close the atmospheric air intake 8 (the state shown in the figure), or close the negative pressure intake lower in response to energization and deenergization of the solenoid SLI. , the air intake port 8 is opened.

Similarly to the negative pressure release valve 10, the movable piece 14. It has a tension coil spring 15 and a solenoid SL2, and the movable piece 14 closes (the illustrated state) or opens the air intake port 9.

In addition, a vacuum pump v, which is an external negative pressure source, is connected between the intake manifold 6 and the negative pressure intake lower communicating therewith.
The inlet of P is in communication. Vacuum pump vP is
Driven by motor M, suction pressure (negative pressure) is applied to the negative pressure intake lower. 18 is a check valve. Note that 16 is an accelerator pedal, and 17 is a tension coil spring.

FIG. 3 shows an outline of the control operation of the microcomputer CPU shown in FIG. 1, and FIGS. 4 and 5.

FIG. 6, FIG. 7, FIG. 8, FIG. 9a, and FIG. 9b.

10a, 10b and 10c show details of the subroutine or interrupt processing routine shown in FIG. 3.

See Figure 3. The microcomputer CPU is W
When the i source is turned on (Sl:S means the step or subroutine of the flowchart, the number indicates the step number or subroutine number attached to the flowchart;
(hereinafter the same meaning), performs initial settings, that is, port status settings, memory clear, parameter initial settings, etc. (S2). After completing the initial settings, the microcomputer CPU performs 3
3 or less processes are repeatedly executed at a cycle of about 50 m5ec.

In S3, the states of input ports P1 to P6 are read. Next, S4. S5. In S6 or S7, it is checked whether any of the brake switch BSW, clutch switch CSW, set switch SSW, or resume switch R8W is on. Brake switch BSW
is on (S4) or clutch switch C8W is on (
S5), set 0 in register S8),
If set switch SSW is on (S6), set 2 to register S (S9), resume switch R3
If W is on (S7), 3 is set in register S (S10).

Then, depending on the contents of register S (Sll), "standby processing J (S12), r constant speed control processing J (S13)"
, r set processing J (S14) or resume processing J (S15), and returns to input port reading (S3). Thereafter, this operation is repeatedly executed in a loop.

Note that even if fuse FS2 is blown, switch BSW
The microcomputer CP
U determines that the switch BSW is turned on both when the input port P2 becomes a high level 1 (and when the input port Pi becomes a low level L).

The external interrupt (S16) will be explained with reference to FIG.

In this example, the external interrupt occurs every time the vehicle speed detection reed switch LSW is turned on, that is, at the fall of the signal applied to the input port P6.

When an external interrupt occurs (S l 6), register R4
(1).As a result, in step 2, if the contents of register R4 is less than 4, the process returns to the main routine, but if the contents of register R4 is 4 or more, the microcomputer CPU is installed inside it. Read the contents of hardware counter CN.

The counter CN always counts clock pulses of a predetermined period apart from the operation of the microcomputer CPU, but is cleared every four times an external interrupt occurs. Therefore, this counter CN has a reed switch LSW for vehicle speed detection.
A value corresponding to the time when four pulses are output is counted. A permanent magnet placed near the reed switch LSW has four poles, and when it rotates once, the reed switch LSW outputs four pulses. In other words, the counter CN measures the time it takes for the speedometer cable to rotate once.

The periodic data obtained by reading the contents of the counter CN is stored in register R5, and when the contents of register R4 becomes 4 or more, the contents of register R4 are cleared (3), and the periodic data stored in register R5 is , the vehicle speed is calculated, and the result is stored in the register RO (4). When these processes are completed, the contents of the counter CN are cleared and restarted (5), and the process returns to the main routine.

Next, timer interrupt processing (S17) will be explained with reference to FIG. In this example, a hardware timer provided internally in the microcomputer CPU is used to generate a timer interrupt request at predetermined intervals. When that timer interrupt request occurs.

The timer interrupt process (S17) shown in FIG. 5 is executed.

In timer interrupt processing (S17), register RA.

Increment Ra (11). These registers are used as independent timers.

Every time the value of register Ra exceeds the predetermined value NA (12),
The contents of register R1 are stored in register R2, and the contents of register R8 are stored in register R1 (13).This process is performed every time the value of register RA exceeds a predetermined value NA, so each register R2 and R, contains the latest vehicle speed and the previously measured vehicle speed, respectively.6 Furthermore, the result of subtracting the value of register R-2 from the value of register R1 is stored in register R1, and the contents of register RA are cleared to 0 (14). . This process is performed periodically at predetermined time intervals determined by the value of NA. The contents of register R3 are used as acceleration data in the duty calculation described later.

Note that the register R, which is incremented in the timer interrupt processing (S17), is used as a timer for determining the on time or off time of various switches. Also, although not shown in Fig. 3, there is a brake switch BSW and a clutch switch CSW.

Set switch SSW or resume switch RSW
When starting from the off state and changing to the on state, the value of the register R is cleared to 0. This allows the elapsed time since each switch was turned on to be determined.

Next, the "standby process J (S12)" will be explained with reference to FIG. When set in this way, both the negative pressure control valve 10 and the negative pressure release valve 11 communicate the negative pressure chamber within the negative pressure actuator 20 with the atmosphere.
The throttle valve 5 moves in a direction that does not open it.

Next, the r set processing J (S14) will be explained with reference to FIG. When the set switch SSW is turned on.

First, set release solenoid SL2 to ON (
31), thereby the negative pressure release valve 11.

Isolate the negative pressure chamber of the negative pressure actuator from the atmosphere.

However, even in this state, the control solenoid SLl remains off, so the negative pressure control valve 10 communicates the negative pressure chamber of the negative pressure actuator with the atmosphere.

If the set switch SSW remains on (
32), then immediately return to the main routine. Therefore, even if the vehicle is in a predetermined running state, if the driver takes his foot off the accelerator pedal 16, the vehicle speed will gradually decrease. When the set switch SSW changes from on to off (
32), the contents of the register RO at that time, that is, the current vehicle speed, are stored in the vehicle speed memory RM (33), and 1 is set in the register S (34). When register S is set to 1, from the next loop processing, the steps shown in FIGS. 9a and 9 will be described later.
The "constant speed control process" (S13) shown in Figure b is executed.

Next, referring to FIG. 8, "resume processing" (S15
). When resume switch R3W is turned on, first set release solenoid SL2 to on (
41). Thereby, the negative pressure release valve 11 isolates the negative pressure chamber of the negative pressure actuator from the atmosphere. Next, check for overflow of the resume timer (42). Note that the resume timer is a register R that is cleared when the resume switch R5W is turned on for the first time.

If there is no overflow, return to the main routine.

When the resume timer overflows (43), the control solenoid SLI should be set to the on state.44
), stores the contents of register Ro in vehicle speed memory R, (
45). When the control solenoid SLI is maintained in the on state, the negative pressure control valve 10 is activated by the negative pressure actuator 2.
0 is connected to a negative pressure system that communicates with the intake manifold 6.

Therefore, in this state, the state of the negative pressure actuator gradually changes in the direction of opening the throttle valve 5, and the vehicle speed gradually increases. When the resume switch R3W turns off (42), register S is set to 1)-L (46),
In the next loop process, “constant speed control process J (S13)
Proceed to.

If the resume switch R3W is turned off before the resume timer overflows, the vehicle speed previously stored in the vehicle speed memory RM is read and the vehicle starts running at a constant speed. However, if the resume timer overflows, the vehicle speed Since the contents of the memory RM are updated to the current vehicle speed, the vehicle enters constant speed driving at the current vehicle speed.

Referring to FIGS. 9a and 9b, "Constant speed control process J (
S13) will be explained. In FIG. 9a, when the duty control timing (every 50 msec) is reached (51), the output duty and integral duty are calculated in the "Constant speed control duty calculation" subroutine (52).

Here, constant speed control duty calculation J (52) will be explained with reference to FIG. 10a, FIG. 10b, and FIG. 10C. See Figure 10a. First, an initial set duty DS is calculated (81).

The initial set duty DS is a duty corresponding to the stored vehicle speed VM required when the vehicle runs on a flat road without disturbance, and is set in advance. Therefore, the initial set duty DS is calculated from the stored vehicle speed VM (the value stored in the register RM).Next, the preset loop gain GV, the stored vehicle speed Vs (the value stored in the register RM), and the current vehicle speed are calculated. Vo (value stored in register R, (corresponding to the contents stored in register R3 in the processing J (S17)).

GVX (VM VOCTXA)” ・ (3,
) is calculated (82), and then the vehicle speed deviation VM-VO is O
Please check if it is smaller than 83).

When VM-VO is smaller than 0, VM-VO
Check if is less than -2,0 km/h (86), -2,
0 to 1/h or less, V x Vo = -2,0
Apply the lower limit to km/h (87). Also, V
When M-Vo is 0 or more, further LmV, -Vo is 5.0
Check if it is more than km/h (84), 1/5.0
If it is more than h, the upper limit is applied to V, -V, = 5.0 as ■/h (85).

The upper limit is for suppressing an excessive increase in the integral value of the positive vehicle speed deviation at the time of climbing, and suppressing the overshoot of the vehicle speed at the end of climbing, and the lower limit is for suppressing the overshoot of the vehicle speed at the end of climbing. During constant speed control, when the driver depresses the accelerator pedal and manually increases the speed during override, a negative vehicle speed deviation occurs and integration is performed.When exiting the vehicle or override is completed, undershoot occurs due to the integral duty DI, which will be described later. This is to prevent Also, when the vehicle speed deviation is negative (when overriding or dismounting)
Limit value (VM-Vo = 2.0km/h
) to be smaller than the limit value (V M -V o = 5.0km/h) when the vehicle speed deviation is positive (when climbing up) to prevent the integral duty from increasing more than necessary when descending or overriding. prevent.

The CPU then executes steps 88, 89, 90A and 90
At B, it is checked whether (1) the running has changed from the uphill road to the downhill road or the flat road, and (2) whether the running has changed from the downhill road to the uphill road or the flat road.

In the case of (1) above, the integral value DI has become a positive and quite large value due to the uphill running up to now. This is checked in step 90A.

Furthermore, since the vehicle has changed from running on an uphill road to running on a downhill road or on a flat road, the throttle opening degree is large according to the integral value DI up to that point, so the vehicle speed deviation becomes negative continuously.

This is checked in step 89. In step 89, VM-VO is the vehicle speed deviation calculated this time, VM-Vl
is the previously calculated vehicle speed deviation.

In these checks, the vehicle speed deviation VM calculated this time
-VO and the vehicle speed deviation VM-Vl calculated last time are both negative (check 89 is YES), and L/may be the integrated value D.
If I (duty conversion value) is +15% or more (90
(Check A is YES), assuming (1) above, a ΔDI increase flag indicating that the integral value is excessively large for the current driving conditions is set (91).

In the case of (2) above, the integral value DI is negative and its absolute value is quite large due to the downhill road travel up to now. This is checked in step 90B. Also, since the driving has changed from a downhill road to an uphill road or a flat road, the throttle opening is small according to the integral value DI up to that point.
Vehicle speed deviation becomes positive continuously. This is checked in step 88. In step 88, the vehicle speed deviation vM-v calculated this time and the vehicle speed deviation vM-v calculated last time.

are both positive (check 88 is YES), and the integrated value DI (duty conversion value) is -15% or less (check 90B is YES), assuming that (2) above exists, Set the ΔDI increase flag indicating that the integral value is excessively large (large on the negative side) for the driving conditions (91), and start the ΔDI increase timer (92).
, Incidentally, until this ΔDI increase timer times out, the addition value for integration is integrated and added with a large gain (0, 04) in the subroutine 103 described later, so the above (1
) or (2), the previously large integral value rapidly decreases, the vehicle speed vo quickly converges to the target vehicle speed VM, and the above (
In the case of 1) or (2), overshoot or undershoot of the traveling vehicle speed with respect to the target vehicle speed is prevented.

See Figure 10b. If there is an integral value ΔDI increase flag (93), the integral value ΔDI increase flag is reset (95) after a predetermined time has elapsed (94).

Check again whether there is an M minute value ΔDI increase flag (96), and if there is no flag, check whether overdrive, which will be described later, is prohibited (97).

If it is not prohibited, check whether the vehicle speed deviation VH-V is smaller than O (98), and if the vehicle speed deviation VM-Vo is 0 or more, further check whether it is outside 2.0 km/hm/99.
), and if the vehicle speed deviation vM-Vo is 2.0 bm/h or more, the current integral addition value ΔDI.

ADI: 0.04X (VM VO) 0.02X2
．． OL: Set (100) Therefore, the integral addition value ΔDI for the current vehicle speed deviation has the relationship shown in FIG. 12a. Vehicle speed deviation VM-V is 2 in step 99,
0 is smaller than ■/h, or when it is smaller than 0 in step 98, the current integral addition value ΔDI is set to ΔDI = 0.02X (Vs-Vo) as shown in ■ in Fig. 12a (101 ).

Note that a limiter is applied when the vehicle speed deviation VH-Vo is -2.0 bm/h or less (according to step 87).
.

Therefore, when the vehicle speed deviation VM-VO exceeds 2.0 + s/h, the integral gain is set large so that the integration is performed quickly, so that the vehicle speed converges quickly to the stored vehicle speed VM at the time of pitching. When descending, when the vehicle speed deviation vM-vo becomes smaller than 0, the duty becomes smaller and the throttle valve 5 is immediately fully closed.For example, when the vehicle speed is 80 km/h, the initial set duty DS is 40%, Since the opening degree is only about 10%, it will soon become fully open as the output duty decreases. Therefore, when the vehicle speed deviation VM-Vo is negative, there is almost no effect due to integration, and there is no problem even if the limiter is small. Note that if the integration is not performed when the vehicle speed deviation vM-vo is negative, the integral value cannot be subtracted when the vehicle transitions from the uphill to the flattened position, resulting in overshoot.To prevent this, the above-mentioned like,
Integration is also performed when the vehicle speed deviation is negative.

When there is an integral value ΔDI increase flag in step 96 (within a predetermined time from the change in stepping down/up), the integral gain is increased as shown in ■ in Fig. 12b, and in step 103
Set I = o, o4x (V MVo ) (twice the gain of ■ in Figure 12a). Therefore.

When the load changes suddenly, such as when the road surface changes from going up to going down (or vice versa), by quickly subtracting the integral value that has been added up to that point, you can eliminate overshoot or undershoot caused by the integral value. Take fewer shots.

In step 97, when overdriving of the transmission mechanism, which will be described later, is prohibited, in step 102, the integral gain is reduced to ΔD I =0.01X (V5-Vo) as shown in ■ in FIG. 1/ of the gain of ■ in the figure
2 times). In other words, if overdrive is prohibited when the vehicle is pitched, the driving force of the vehicle system will increase.

Therefore, if the output duty is corrected using the integral gain while running in overdrive, the gain will be too large and cause hunting, etc. Therefore, when overdrive is prohibited, the integral gain is made smaller than when running in overdrive.

In step 104, the previous integral duty DI and the integral addition value ΔDI are added together using the code material, and the one-way work area WOR is added.
Stored in K. Additionally, this value is limited to 40% (105.106).

See Figure 10c. In step 107, the initial set duty DS (81) and the value of equation (3) in step 82 are added to set the output duty DV. The lower limit of the output duty DV is 3% (108, 11
1), the upper limit is limited to 97% (109.11
0). The output duty DV is updated in step 112, but the output duty DV is limited at the lower limit (11
3,117), or limit at the upper limit (114,11
5), the process does not proceed to step 116, so the current integration action is ignored and no integration is performed.

In other words, when a vehicle speed deviation V, -V occurs and this state continues for a long time, the integral duty DI gradually increases due to integration, and as a result, the calculated output duty DV also increases and exceeds the limit value (97%). Become. If this state continues, only the integral duty continues to increase while the duty continues to output 97%. The integral value at this time does not increase the output duty, but the increased integral duty only causes an increase in overshoot when the rider descends from the pitch. Therefore, when the output duty DV exceeds the limit value, the integral addition value ΔDI at that time is invalidated (zero). The same applies when leaving the board.

Referring again to FIG. 9a. In step 53, when the output duty DV calculated in the constant speed control duty calculation J (52) is set, the solenoid SLI of the negative pressure control valve 10 is duty-controlled at a predetermined period (every 50a+sec).

Next, when the integral duty DI becomes 25% (5
7) Turn on the motor M that drives the vacuum pump vP (58). Also, while the vacuum pump vP is on, the vehicle speed deviation V, -V is 1. When it becomes less than Okm/h (5
5) Turn off the motor M that drives the vacuum pump vP (56). Note that the vacuum pump vP may be turned off when the integral duty DI becomes equal to or less than a predetermined value. In other words, when the vehicle is on the hill, the vehicle speed decreases and vehicle speed deviation ■8-■o occurs, so the opening degree of the throttle valve 5 increases in an attempt to increase the output duty, but the negative pressure in the intake manifold is low and the negative pressure actuator 20 Since the pressure in the negative pressure chamber inside decreases, even if the output duty is increased, the force generated by the negative pressure actuator 200 will not increase, and the throttle valve 20 will not be able to open beyond a certain opening degree.To prevent this, Additionally, use an external negative pressure source (vacuum pump VP).

In step 59, immediately after the vacuum pump vP is driven from off to on, the integral duty DI is set to a predetermined value (
10%) (60). As a result, the negative pressure caused by the negative pressure actuator 20 decreases, and the output duty DV
Vacuum pump ■P is turned on from a state where the pressure is high, and the sudden increase in negative pressure increases the throttle opening and prevents the vehicle from accelerating excessively.

See Figure 9b. When the integral duty DI is 30% or more, (62) overdrive is prohibited and register T is
Set sdc to 1 (63). In other words, when the vehicle speed decreases and the output duty DV increases, the vehicle speed may gradually decrease if the driving force is insufficient. improve. In addition, after prohibiting the -carrier overdrive, the vehicle speed deviation V, -Vo is 2.0km/
When it becomes less than h (64), overdrive prohibition is canceled and T_sdc is set to 0 (65). Note that the overdrive prohibition may be canceled when the integral duty DI becomes less than a predetermined value.

Immediately after overdrive is changed from permitted to prohibited in step 66, the integral duty DI is reduced by a predetermined value (15%) (67). When the output duty is increased by DI, the driving force suddenly increases and acceleration is prevented.

In step 69, the phase within the duty control period is checked using register R. and register R1
The content of 1 is (69
) Set the control solenoid SLl to ON7.
0), from the output duty DV to DVmax (duty control period) (72), the control solenoid SLI is set to OFF (71). In step 72, when R exceeds DVmax, that is, each time one cycle of duty control is completed, the contents of register RB are cleared (73) and time measurement for the next cycle is started.

Timing is performed by a timer interrupt (S17) in FIG.

Therefore, when the control solenoid SLI is controlled on/off according to the calculated output duty DV, the negative pressure control valve lO connects the negative pressure chamber of the negative pressure actuator 20 alternately to the negative pressure system and the atmosphere accordingly. . As a result, the pressure in the negative pressure chamber inside the negative pressure actuator is reduced to duty DV.
The corresponding value is gu, and the opening degree of the throttle valve 5 is determined accordingly.

Next, referring to FIG. 11, the processing operations of the speed change controller 31 will be explained. When the speed change controller 31 is powered on, it executes initialization and initial setting (120 and 121). Then, the input is read (122), and then it is checked whether the signal Tsdc from the microcomputer CPU is 1 (shift down designation) (123), and the processing corresponding to Tsdc is performed. will be described later.

After passing through this processing step, a shift lever position shift determination is performed, and here, shift lever switching detection, N (neutral) position detection, etc. are performed (127).
If it is in the N position, it returns to reading again (122), and the shift lever changes from N to D (drive).

2 or 1, in determining the speed change reference data (128), the speed change reference data to be referred to for upshifting or downshifting the speed step (maintaining each speed step, shifting up or down, throttle Maximum or minimum value of vehicle speed for opening degree: Determines whether to shift up when the traveling vehicle speed exceeds the maximum value, or downshift when it is below the low value. Hereinafter, 1→2 shift (upshift) control (129), 2→1 shift (downshift) control (130), 2→3 shift control (132),
3→2 shift control (133), 3→4 shift control (summer 35), 4→3 shift control (136), and lock-up control (137) are performed, and reading (122) to lock-up control (137) are repeated. In the shift control, the shift reference data assigned to the current speed stage.

The current vehicle speed is compared with the maximum and minimum vehicle speed values assigned to the current throttle opening, and if the current vehicle speed is higher than the maximum value, it is determined that an upshift is required, and if the current vehicle speed is lower than the minimum value, it is determined that an upshift is required. It is determined that a downshift is required. If it is determined that an upshift or downshift is necessary, the lockup is released and then the upshift or downshift is executed. When it is not determined that a shift up is necessary, and neither is it determined that a downshift is necessary, the speed stage is not changed and the process proceeds to the first step.

In lock-up control (137), the current vehicle speed is assigned to the current throttle opening of the vehicle speed maximum value (corresponding to throttle opening) and minimum value (corresponding to throttle opening) assigned to the currently set speed stage. Compare the vehicle speed and the vehicle speed a, and if T11° vehicle speed is higher than the maximum value, lock-up occurs. &Lockup is released when the value is below the low value.

The shift control and lock-up control described above are disclosed in detail in the aforementioned Japanese Patent Application Laid-Open No. 56-39354, so a detailed explanation thereof will be omitted here.

Now, the above-mentioned shift down instruction (Tsdc=1) from the microcomputer CPU has been responded to.

The control operation of the speed change controller 31 will be explained.

The speed change controller 31 reads (122) the signal level of the signal Tsdc from the microcomputer CPU, checks whether it is 1 (shift down instruction) (123), and checks if it is 1 (123). If there,
It is checked whether there is a flag (Fsdn = l) indicating that a downshift corresponding to the downshift instruction has already been performed (124), and if there is not (a downshift has been instructed but the downshift has not yet been performed), The lock-up is released and the speed stage of the transmission mechanism 22-23 is set to one stage lower than the one currently set (+25), and 1 is written in the register Fsdn (126). After that, F
Since sdn is 1, in steps 131 and 134, since the contents of register F sdn are 1, 2→3 shift control (132) and 3→4 shift control (135) are skipped, so these upshifts are performed. Not executed. Downshifting is performed when the conditions are right.

When downshifting and inhibiting upshifting in this way, the microcomputer CPU outputs the signal Ts.
When dc is shifted down to 0 (number a is released), the shift controller 31 reads this (+22) and clears the contents of the register Fsdn in step 138 after passing through step 123.Nio 1 performs 2→3 shift control. (1
32) and 3→4 shift control (135) are executed, and if the conditions are met, an upshift is performed.

〔Effect of the invention〕

As described above, according to the vehicle speed control device of the present invention, the vehicle speed deviation (
When integrating the vehicle speed deviation (Rx
Set limits (upper limit = 5.0/h, lower limit knee 0.2 km/h) to the size of vehicle speed deviation (RM
-RO) is negative, the limit value (-0,2km/h
) is smaller than the supply value of the limit value (5.0km/h) when the vehicle speed deviation (Rs Ro) is positive (1-0.2kin/h l < l 5.Okm/
h I ), when the vehicle speed deviation (RM RO) is positive, the current vehicle speed (Ro) quickly converges to the memorized vehicle speed (RM) due to quick integration. Further, when the driver increases the speed by pressing the accelerator pedal while driving at a constant speed, the integration is performed slowly, so it is possible to suppress the undershoot of the vehicle speed that occurs due to the integral term at the end of the override.

Stability is achieved in constant speed driving conditions. Moreover, since there is no need to newly install a sensor or the like to detect accelerator operation, there is no increase in costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an electric control circuit of a constant speed traveling device according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing the negative pressure actuator 20 included in the device shown in FIG. FIG. 3 is a flowchart showing the general operation of the microcomputer CPU shown in FIG. Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9a,
9b, 10a, 10b and 10c are flowcharts showing the subroutine and interrupt processing shown in FIG. 3. FIG. 11 is a flowchart showing the control operation of the microcomputer CPU of the speed change controller 31 shown in FIG. FIGS. 12a, 12b, and 12c are graphs showing the relationship between the vehicle speed deviation VM-V and the integral addition value ΔDI. 1, la, lb: housing 2: diaphragm 3:
Compression coil spring 4: Protrusion 5: Throttle valve 6: Intake manifold 7: Negative pressure intake 8, 9: Atmospheric intake RO: Negative pressure control valve 11: Negative pressure release valve 12.14: Movable piece
13, 15, 17: Tension coil spring 16: Accelerator pedal 18: Check valve 20: Negative pressure actuator (throttle drive hand (support) 21: Torque converter 22 Niopatribe mechanism 23: Gear transmission mechanism 24: Output shaft 25: Shift lever position sensor 26, 27: Switching solenoid valve 28 Two-rotation up solenoid valve 29: Rotating shaft 30 Nispeed detection circuit 31: Shift front roller LSW: Reed switch Mag: Rotating permanent magnet LSW, Mag:
Ren degree detection assisting CPU: Microcomputer Side degree hand (support) LP Nistop lamp BSW Nibrake switch CS
W: Clutch switch SSW: Set switch R3
W: Resume switch FSI, FS2: Fuse B
T: Battery VRG: Voltage stabilization circuit [
FC: Interface circuit SDI, SD2: Solenoid driver SLI, SL2: Solenoid P: Fulcrum MD: Motor driver M: Motor ■ P: Vacuum pump voice 3 Figure 4 Figure 5 Figure 9a Figure East 9b Figure 10c Figure 12a Illustration 12b Illustration 12c

Claims (1)

[Scope of Claims] Throttle drive means coupled to the throttle valve of the vehicle; Vehicle speed detection means that generates an electrical signal according to the speed of the vehicle; and Accumulates and integrates the deviation between the target speed and the running speed. Speed control means for biasing the throttle drive means in a direction in which the traveling speed matches the target speed in accordance with the value; In the constant speed traveling control device, the speed control means is configured to calculate the deviation = target speed - traveling speed. If the speed is positive, if the deviation is greater than or equal to the first predetermined value, the first predetermined value is integrated; if the deviation is less than the first predetermined value, the deviation is integrated; if the deviation is negative, the first predetermined value is integrated; When the deviation is less than or equal to a second predetermined value whose absolute value is smaller than the first predetermined value, the second predetermined value is integrated, and when it exceeds the second predetermined value, the deviation is integrated. Constant speed driving control device.